On the code side the use of HTML::Template looks like this:
my $template = HTML::Template->new( filename => $dir . '/templates/spip_css.tmpl' );
$template->param(PAGEBACKGROUND => $config->{css}->{pagebackground}); $template->param(TEXTCOLOR => $config->{css}->{textcolor} ); $template->param(TEXTFONT => $config->{css}->{textfont} ); $template->param(FONTSIZE => $config->{css}->{fontsize} ); ...